This application claims the benefit of China application No. 201110244537.9, filed on Aug. 21, 2011.
1. Field of the Invention
The invention relates to touch sensing technique, and more particularly to a touch sensing method and touch sensing device for a sensing array.
2. Description of the Related Art
FIG. 1A shows a sensing row of a touch sensing array, which has been touched by one single object. Referring to FIG. 1A, a sensing row 10 comprises a plurality of sensing cells C1-1˜C1-14 disposed in a line. Generally, one touch sensing operation for the sensing row 10 causes one series of sensing data signals read from the sensing row 10. For example, when one single object 11 (such as a finger, that is one single touch point) touches a position near the sensing cells C1-6 and C1-7 in the sensing row 10, the intensity of the sensing data signals read from the sensing cells C1-1˜C1-14 can be represented by a Gaussian Curve. In some applications, the sensing row 10 may be touched by a plurality of objects. Referring to FIG. 2, one object 20 touches a position near the sensing cells C1-4 in the sensing row 10, while another object touches a position near the sensing cells C1-8 in the sensing row 10. The intensity of the sensing data signals read from the sensing cells C1-1˜C1-14 can be represented by two Gaussian Curves.
In prior arts, according to Gaussian Curve, real data generated when the sensing row 10 is touched can be distinguished from interference noise. Generally, a minimum threshold value is set to determine read data. However, if the touched area on the sensing row 10 is relatively small, the real data generated when the sensing row 10 is touched, may be treated as the interference noise. Thus, in this situation, the setting of the minimum threshold value for Gaussian Curve becomes a moot purpose.
Thus, it is desired to provide a touch sensing method and touch sensing devices that can accurately detect a touch condition of a sensing array, such as a position of an object touching the sensing array.